Multiple security issues have been found in Iceweasel, Debian's version
of the Mozilla Firefox web browser: Multiple memory safety errors,
missing input sanitising vulnerabilities, use-after-free vulnerabilities,
buffer overflows and other programming errors may lead to the execution
of arbitrary code, privilege escalation, information leaks or
cross-site-scripting.

We're changing the approach for security updates for Iceweasel, Icedove
and Iceape in stable-security: Instead of backporting security fixes,
we now provide releases based on the Extended Support Release branch. As
such, this update introduces packages based on Firefox 17 and at some
point in the future we will switch to the next ESR branch once ESR 17
has reached it's end of life.

Some Xul extensions currently packaged in the Debian archive are not
compatible with the new browser engine. Up-to-date and compatible
versions can be retrieved from http://addons.mozilla.org as a short
term solution. A solution to keep packaged extensions compatible with
the Mozilla releases is still being sorted out.

We don't have the resources to backport security fixes to the Iceweasel
release in oldstable-security any longer. If you're up to the task and
want to help, please get in touch with team@security.debian.org.
Otherwise, we'll announce the end of security support for Iceweasel,
Icedove and Iceape in Squeeze in the next update round.

For the stable distribution (wheezy), these problems have been fixed in
version 17.0.6esr-1~deb7u1.

For the unstable distribution (sid), these problems have been fixed in
version 17.0.6esr-1.